* [PATCH 2/3] Add new open_init_pty that doesn't waste CPU time
2012-07-05 18:48 [PATCH 0/3] Patches from the Debian policycoreutils package Laurent Bigonville
2012-07-05 18:48 ` [PATCH 1/3] Patch for mcstrans to not abort when it sees a squeeze config file Laurent Bigonville
@ 2012-07-05 18:48 ` Laurent Bigonville
2012-07-05 18:48 ` [PATCH 3/3] Remove policycoreutils/run_init/open_init_pty.c Laurent Bigonville
2 siblings, 0 replies; 4+ messages in thread
From: Laurent Bigonville @ 2012-07-05 18:48 UTC (permalink / raw)
To: selinux
From: Russell Coker <russell@coker.com.au>
---
policycoreutils/run_init/Makefile | 11 +-
policycoreutils/run_init/open_init_pty.cpp | 423 ++++++++++++++++++++++++++++
2 files changed, 429 insertions(+), 5 deletions(-)
create mode 100644 policycoreutils/run_init/open_init_pty.cpp
diff --git a/policycoreutils/run_init/Makefile b/policycoreutils/run_init/Makefile
index 12b39b4..f3c5e0a 100644
--- a/policycoreutils/run_init/Makefile
+++ b/policycoreutils/run_init/Makefile
@@ -8,8 +8,9 @@ LOCALEDIR ?= /usr/share/locale
PAMH = $(shell ls /usr/include/security/pam_appl.h 2>/dev/null)
AUDITH = $(shell ls /usr/include/libaudit.h 2>/dev/null)
-CFLAGS ?= -Werror -Wall -W
+CFLAGS ?= -Werror -Wall -W -g -O2
override CFLAGS += -I$(PREFIX)/include -DUSE_NLS -DLOCALEDIR="\"$(LOCALEDIR)\"" -DPACKAGE="\"policycoreutils\""
+CPPFLAGS ?= $(CFLAGS)
LDLIBS += -lselinux -L$(PREFIX)/lib
ifeq ($(PAMH), /usr/include/security/pam_appl.h)
override CFLAGS += -DUSE_PAM
@@ -23,17 +24,17 @@ ifeq ($(AUDITH), /usr/include/libaudit.h)
LDLIBS += -laudit
endif
-TARGETS=$(patsubst %.c,%,$(wildcard *.c))
+TARGETS=open_init_pty run_init
all: $(TARGETS)
-open_init_pty: open_init_pty.c
- $(LINK.c) $^ -ldl -lutil -o $@
+open_init_pty: open_init_pty.cpp
+ $(LINK.cpp) $^ -ldl -lutil -o $@
install: all
test -d $(SBINDIR) || install -m 755 -d $(SBINDIR)
- test -d $(MANDIR)/man1 || install -m 755 -d $(MANDIR)/man1
+ test -d $(MANDIR)/man8 || install -m 755 -d $(MANDIR)/man8
install -m 755 run_init $(SBINDIR)
install -m 755 open_init_pty $(SBINDIR)
install -m 644 run_init.8 $(MANDIR)/man8/
diff --git a/policycoreutils/run_init/open_init_pty.cpp b/policycoreutils/run_init/open_init_pty.cpp
new file mode 100644
index 0000000..c892b20
--- /dev/null
+++ b/policycoreutils/run_init/open_init_pty.cpp
@@ -0,0 +1,423 @@
+/* -*- Mode: C -*-
+ * open_init_pty.c ---
+ * Author : Manoj Srivastava ( srivasta@glaurung.internal.golden-gryphon.com )
+ * Created On : Fri Jan 14 10:48:28 2005
+ * Created On Node : glaurung.internal.golden-gryphon.com
+ * Last Modified By : Manoj Srivastava
+ * Last Modified On : Thu Sep 15 00:57:00 2005
+ * Last Machine Used: glaurung.internal.golden-gryphon.com
+ * Update Count : 92
+ * Status : Unknown, Use with caution!
+ * HISTORY :
+ * Description :
+ *
+ * Distributed under the terms of the GNU General Public License v2
+ *
+ * open_init_pty
+ *
+ * SYNOPSIS:
+ *
+ * This program allows a systems administrator to execute daemons
+ * which need to work in the initrc domain, and which need to have
+ * pty's as system_u:system_r:initrc_t
+ *
+ * USAGE:
+ *
+ * * arch-tag: a5583d39-72b9-4cdf-ba1b-5678ea4cbe20
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+
+#include <sysexits.h>
+
+#include <pty.h> /* for openpty and forkpty */
+#include <utmp.h> /* for login_tty */
+#include <termios.h>
+#include <fcntl.h>
+
+#include <sys/select.h>
+#include <sys/wait.h>
+
+
+#define MAXRETR 3 /* The max number of IO retries on a fd */
+#define BUFSIZE 2048 /* The ring buffer size */
+
+static struct termios saved_termios;
+static int saved_fd = -1;
+static enum { RESET, RAW, CBREAK } tty_state = RESET;
+
+static int tty_semi_raw(int fd)
+{
+ struct termios buf;
+
+ if (tty_state == RESET) {
+ if (tcgetattr(fd, &saved_termios) < 0) {
+ return -1;
+ }
+ }
+
+ buf = saved_termios;
+ /*
+ * echo off, canonical mode off, extended input processing off,
+ * signal chars off
+ */
+ buf.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+ /*
+ * no SIGINT on break, CR-to-NL off, input parity check off, do not
+ * strip 8th bit on input,output flow control off
+ */
+ buf.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+ /* Clear size bits, parity checking off */
+ buf.c_cflag &= ~(CSIZE | PARENB);
+ /* set 8 bits/char */
+ buf.c_cflag |= CS8;
+ /* Output processing off
+ buf.c_oflag &= ~(OPOST); */
+
+ buf.c_cc[VMIN] = 1; /* one byte at a time, no timer */
+ buf.c_cc[VTIME] = 0;
+ if (tcsetattr(fd, TCSANOW, &buf) < 0) {
+ return -1;
+ }
+ tty_state = RAW;
+ saved_fd = fd;
+ return 0;
+}
+
+static void tty_atexit(void)
+{
+ if (tty_state != CBREAK && tty_state != RAW) {
+ return;
+ }
+
+ if (tcsetattr(saved_fd, TCSANOW, &saved_termios) < 0) {
+ return;
+ }
+ tty_state = RESET;
+ return;
+}
+
+
+/* The simple ring buffer */
+class ring_buffer
+{
+public:
+ ring_buffer(char *buf, size_t size)
+ {
+ m_buf = m_wptr = m_rptr = buf;
+ m_size = size;
+ m_count = 0;
+ }
+
+ size_t get_count() { return m_count; }
+ int isempty() { return m_count == 0; }
+
+ // return the unused space size in the buffer
+ size_t space()
+ {
+ if(m_rptr > m_wptr)
+ return m_rptr - m_wptr;
+ if(m_rptr < m_wptr || m_count == 0)
+ return m_buf + m_size - m_wptr;
+ return 0; // should not hit this
+ }
+
+ // return the used space in the buffer
+ size_t chunk_size()
+ {
+ if(m_rptr < m_wptr)
+ return m_wptr - m_rptr;
+ if(m_rptr > m_wptr || m_count > 0)
+ return m_buf + m_size - m_rptr;
+ return 0; // should not hit this
+ }
+
+ // read from fd and write to buffer memory
+ ssize_t rb_read(int fd)
+ {
+ ssize_t n = read(fd, m_wptr, space());
+ if(n <= 0)
+ return n;
+ m_wptr += n;
+ m_count += n;
+ if(m_buf + m_size <= m_wptr)
+ m_wptr = m_buf;
+ return n;
+ }
+
+ ssize_t rb_write(int fd)
+ {
+ ssize_t n = write(fd, m_rptr, chunk_size());
+ if(n <= 0)
+ return n;
+ m_rptr += n;
+ m_count -= n;
+ if(m_buf + m_size <= m_rptr)
+ m_rptr = m_buf;
+ return n;
+ }
+
+private:
+ char *m_buf; /* pointer to buffer memory */
+ char *m_wptr;
+ char *m_rptr;
+ size_t m_size; /* the number of bytes allocated for buf */
+ size_t m_count;
+};
+
+static void setfd_nonblock(int fd)
+{
+ int fsflags = fcntl(fd, F_GETFL);
+
+ if (fsflags < 0) {
+ fprintf(stderr, "fcntl(%d, F_GETFL): %s\n",
+ fd, strerror(errno));
+ exit(EX_IOERR);
+ }
+
+ if (fcntl(STDIN_FILENO, F_SETFL, fsflags | O_NONBLOCK) < 0) {
+ fprintf(stderr, "fcntl(%d, F_SETFL, ... | O_NONBLOCK): %s\n",
+ fd, strerror(errno));
+ exit(EX_IOERR);
+ }
+}
+
+static void sigchld_handler(int asig __attribute__ ((unused)))
+{
+}
+
+int main(int argc, char *argv[])
+{
+ pid_t child_pid;
+ int child_exit_status;
+ struct termios tty_attr;
+ struct winsize window_size;
+ int pty_master;
+ char inbuf_mem[BUFSIZE];
+ char outbuf_mem[BUFSIZE];
+ ring_buffer inbuf(inbuf_mem, sizeof(inbuf_mem));
+ ring_buffer outbuf(outbuf_mem, sizeof(outbuf_mem));
+
+ if (argc == 1) {
+ printf("usage: %s PROGRAM [ARGS]...\n", argv[0]);
+ exit(1);
+ }
+
+ /* Wee need I/O calls to fail with EINTR on SIGCHLD... */
+ if ( signal(SIGCHLD, sigchld_handler) == SIG_ERR ) {
+ perror("signal(SIGCHLD,...)");
+ exit(EX_OSERR);
+ }
+
+ if (isatty(STDIN_FILENO)) {
+ /* get terminal parameters associated with stdout */
+ if (tcgetattr(STDOUT_FILENO, &tty_attr) < 0) {
+ perror("tcgetattr(stdout,...)");
+ exit(EX_OSERR);
+ }
+
+ /* end of if(tcsetattr(&tty_attr)) */
+ /* get window size */
+ if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &window_size) < 0) {
+ perror("ioctl(stdout,...)");
+ exit(1);
+ }
+
+ child_pid = forkpty(&pty_master, NULL, &tty_attr, &window_size);
+ } /* end of if(isatty(STDIN_FILENO)) */
+ else { /* not interactive */
+ child_pid = forkpty(&pty_master, NULL, NULL, NULL);
+ }
+
+ if (child_pid < 0) {
+ perror("forkpty()");
+ fflush(stdout);
+ fflush(stderr);
+ exit(EX_OSERR);
+ } /* end of if(child_pid < 0) */
+ if (child_pid == 0) {
+ /* in the child */
+ struct termios s_tty_attr;
+ if (tcgetattr(STDIN_FILENO, &s_tty_attr)) {
+ perror("tcgetattr(stdin,...)");
+ exit(EXIT_FAILURE);
+ }
+ /* Turn off echo */
+ s_tty_attr.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
+ /* Also turn of NL to CR?LF on output */
+ s_tty_attr.c_oflag &= ~(ONLCR);
+ if (tcsetattr(STDIN_FILENO, TCSANOW, &s_tty_attr)) {
+ perror("tcsetattr(stdin,...)");
+ exit(EXIT_FAILURE);
+ }
+
+ if (execvp(argv[1], argv + 1)) {
+ perror("execvp()");
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ /*
+ * Non blocking mode for all file descriptors.
+ */
+ setfd_nonblock(pty_master);
+ setfd_nonblock(STDIN_FILENO);
+ setfd_nonblock(STDOUT_FILENO);
+
+ if (isatty(STDIN_FILENO)) {
+ if (tty_semi_raw(STDIN_FILENO) < 0) {
+ perror("tty_semi_raw(stdin)");
+ }
+ if (atexit(tty_atexit) < 0) {
+ perror("atexit()");
+ }
+ }
+
+ /* for select()... */
+ fd_set readfds;
+ fd_set writefds;
+ fd_set exceptfds;
+ FD_ZERO(&readfds);
+ FD_ZERO(&writefds);
+ FD_ZERO(&exceptfds);
+
+ unsigned err_n_rpty = 0;
+ unsigned err_n_wpty = 0;
+ unsigned err_n_stdin = 0;
+ unsigned err_n_stdout = 0;
+
+ int done = 0;
+
+ do {
+ /* Accept events only on fds, that we can handle now. */
+ int do_select = 0;
+
+ if ( outbuf.space() > 0 && err_n_rpty < MAXRETR ) {
+ FD_SET(pty_master, &readfds);
+ do_select = 1;
+ } else
+ FD_CLR(pty_master, &readfds);
+
+ if ( ! inbuf.isempty() && err_n_wpty < MAXRETR ) {
+ FD_SET(pty_master, &writefds);
+ do_select = 1;
+ } else
+ FD_CLR(pty_master, &writefds);
+
+ if ( inbuf.space() > 0 && err_n_stdin < MAXRETR ) {
+ FD_SET(STDIN_FILENO, &readfds);
+ do_select = 1;
+ } else
+ FD_CLR(STDIN_FILENO, &readfds);
+
+ if ( ! outbuf.isempty() && err_n_stdout < MAXRETR ) {
+ FD_SET(STDOUT_FILENO, &writefds);
+ do_select = 1;
+ } else
+ FD_CLR(STDOUT_FILENO, &writefds);
+
+ if ( ! do_select )
+ {
+#ifdef DEBUG
+ fprintf(stderr, "No I/O job for us, calling waitpid()...\n");
+#endif
+ while ( waitpid(child_pid, &child_exit_status, 0) < 0 )
+ ;
+ break;
+ }
+
+ int select_rc = select(pty_master + 1,
+ &readfds, &writefds, &exceptfds, NULL);
+ if ( select_rc < 0 ) {
+ perror("select()");
+ exit(EX_IOERR);
+ }
+#ifdef DEBUG
+ fprintf(stderr, "select() returned %d\n", select_rc);
+#endif
+
+ if (FD_ISSET(STDOUT_FILENO, &writefds)) {
+#ifdef DEBUG
+ fprintf(stderr, "stdout can be written\n");
+#endif
+ ssize_t n = outbuf.rb_write(STDOUT_FILENO);
+ if ( n <= 0 && n != EINTR && n != EAGAIN )
+ err_n_stdout++;
+#ifdef DEBUG
+ if ( n >= 0 )
+ fprintf(stderr, "%d bytes written into stdout\n", n);
+ else
+ perror("write(stdout,...)");
+#endif
+ }
+ if (FD_ISSET(pty_master, &writefds)) {
+#ifdef DEBUG
+ fprintf(stderr, "pty_master can be written\n");
+#endif
+ ssize_t n = inbuf.rb_write(pty_master);
+ if ( n <= 0 && n != EINTR && n != EAGAIN )
+ err_n_wpty++;
+#ifdef DEBUG
+ if ( n >= 0 )
+ fprintf(stderr, "%d bytes written into pty_master\n", n);
+ else
+ perror("write(pty_master,...)");
+#endif
+ }
+ if (FD_ISSET(STDIN_FILENO, &readfds)) {
+#ifdef DEBUG
+ fprintf(stderr, "stdin can be read\n");
+#endif
+ ssize_t n = inbuf.rb_read(STDIN_FILENO);
+ if ( n <= 0 && n != EINTR && n != EAGAIN )
+ err_n_stdin++;
+#ifdef DEBUG
+ if ( n >= 0 )
+ fprintf(stderr, "%d bytes read from stdin\n", n);
+ else
+ perror("read(stdin,...)");
+#endif
+ }
+ if (FD_ISSET(pty_master, &readfds)) {
+#ifdef DEBUG
+ fprintf(stderr, "pty_master can be read\n");
+#endif
+ ssize_t n = outbuf.rb_read(pty_master);
+ if ( n <= 0 && n != EINTR && n != EAGAIN )
+ err_n_rpty++;
+#ifdef DEBUG
+ if ( n >= 0 )
+ fprintf(stderr, "%d bytes read from pty_master\n", n);
+ else
+ perror("read(pty_master,...)");
+#endif
+ }
+
+ if ( ! done )
+ if ( waitpid(child_pid, &child_exit_status, WNOHANG) > 0 )
+ done = 1;
+
+ } while ( !done
+ || !(inbuf.isempty() || err_n_wpty >= MAXRETR)
+ || !(outbuf.isempty() || err_n_stdout >= MAXRETR) );
+
+#ifdef DEBUG
+ fprintf(stderr, "inbuf: %u bytes left, outbuf: %u bytes left\n",
+ inbuf.get_count(), outbuf.get_count());
+ fprintf(stderr, "err_n_rpty=%u, err_n_wpty=%u, "
+ "err_n_stdin=%u, err_n_stdout=%u\n",
+ err_n_rpty, err_n_wpty, err_n_stdin, err_n_stdout);
+#endif
+ if ( WIFEXITED(child_exit_status) )
+ exit(WEXITSTATUS(child_exit_status));
+ exit(EXIT_FAILURE);
+} /* end of main() */
+
+/*
+ * vim:ts=4:
+ */
--
1.7.10
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 3/3] Remove policycoreutils/run_init/open_init_pty.c
2012-07-05 18:48 [PATCH 0/3] Patches from the Debian policycoreutils package Laurent Bigonville
2012-07-05 18:48 ` [PATCH 1/3] Patch for mcstrans to not abort when it sees a squeeze config file Laurent Bigonville
2012-07-05 18:48 ` [PATCH 2/3] Add new open_init_pty that doesn't waste CPU time Laurent Bigonville
@ 2012-07-05 18:48 ` Laurent Bigonville
2 siblings, 0 replies; 4+ messages in thread
From: Laurent Bigonville @ 2012-07-05 18:48 UTC (permalink / raw)
To: selinux
From: Laurent Bigonville <bigon@bigon.be>
---
policycoreutils/run_init/open_init_pty.c | 399 ------------------------------
1 file changed, 399 deletions(-)
delete mode 100644 policycoreutils/run_init/open_init_pty.c
diff --git a/policycoreutils/run_init/open_init_pty.c b/policycoreutils/run_init/open_init_pty.c
deleted file mode 100644
index 4f04e72..0000000
--- a/policycoreutils/run_init/open_init_pty.c
+++ /dev/null
@@ -1,399 +0,0 @@
-/* -*- Mode: C -*-
- * open_init_pty.c ---
- * Author : Manoj Srivastava ( srivasta@glaurung.internal.golden-gryphon.com )
- * Created On : Fri Jan 14 10:48:28 2005
- * Created On Node : glaurung.internal.golden-gryphon.com
- * Last Modified By : Manoj Srivastava
- * Last Modified On : Thu Sep 15 00:57:00 2005
- * Last Machine Used: glaurung.internal.golden-gryphon.com
- * Update Count : 92
- * Status : Unknown, Use with caution!
- * HISTORY :
- * Description :
- *
- * Distributed under the terms of the GNU General Public License v2
- *
- * open_init_pty
- *
- * SYNOPSIS:
- *
- * This program allows a systems administrator to execute daemons
- * which need to work in the initrc domain, and which need to have
- * pty's as system_u:system_r:initrc_t
- *
- * USAGE:
- *
- * * arch-tag: a5583d39-72b9-4cdf-ba1b-5678ea4cbe20
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <signal.h>
-#include <errno.h>
-
-#include <sysexits.h>
-
-#include <pty.h> /* for openpty and forkpty */
-#include <utmp.h> /* for login_tty */
-#include <termios.h>
-#include <fcntl.h>
-
-#include <sys/select.h>
-
-static struct termios saved_termios;
-static int saved_fd = -1;
-static enum { RESET, RAW, CBREAK } tty_state = RESET;
-
-static int tty_semi_raw(int fd)
-{
- struct termios buf;
-
- if (tty_state == RESET) {
- if (tcgetattr(fd, &saved_termios) < 0) {
- return -1;
- }
- }
-
- buf = saved_termios;
- /*
- * echo off, canonical mode off, extended input processing off,
- * signal chars off
- */
- buf.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
- /*
- * no SIGINT on break, CR-to-NL off, input parity check off, do not
- * strip 8th bit on input,output flow control off
- */
- buf.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
- /* Clear size bits, parity checking off */
- buf.c_cflag &= ~(CSIZE | PARENB);
- /* set 8 bits/char */
- buf.c_cflag |= CS8;
- /* Output processing off
- buf.c_oflag &= ~(OPOST); */
-
- buf.c_cc[VMIN] = 1; /* one byte at a time, no timer */
- buf.c_cc[VTIME] = 0;
- if (tcsetattr(fd, TCSANOW, &buf) < 0) {
- return -1;
- } /* end of if(tcsetattr(fileno(stdin), TCSANOW, &buf) < 0) */
- tty_state = RAW;
- saved_fd = fd;
- return 0;
-}
-
-void tty_atexit(void)
-{
- if (tty_state != CBREAK && tty_state != RAW) {
- return;
- }
-
- if (tcsetattr(saved_fd, TCSANOW, &saved_termios) < 0) {
- return;
- } /* end of if(tcsetattr(fileno(stdin), TCSANOW, &buf) < 0) */
- tty_state = RESET;
- return;
-}
-
-int main(int argc, char *argv[])
-{
- pid_t child_pid;
- struct termios tty_attr;
- struct winsize window_size;
- int pty_master;
- int retval = 0;
-
- /* for select */
- fd_set readfds;
- fd_set writefds;
- fd_set exceptfds;
-
- int err_count = 0;
-
- /* for sigtimedwait() */
- struct timespec timeout;
- char buf[16384];
-
- if (argc == 1) {
- printf("usage: %s PROGRAM [ARGS]...\n", argv[0]);
- exit(1);
- }
-
- sigset_t signal_set;
- siginfo_t signalinfo;
-
- /* set up SIGCHLD */
- sigemptyset(&signal_set); /* no signals */
- sigaddset(&signal_set, SIGCHLD); /* Add sig child */
- sigprocmask(SIG_BLOCK, &signal_set, NULL); /* Block the signal */
-
- /* Set both to 0, so sigtimed wait just does a poll */
- timeout.tv_sec = 0;
- timeout.tv_nsec = 0;
-
- if (isatty(fileno(stdin))) {
- /* get terminal parameters associated with stdout */
- if (tcgetattr(fileno(stdout), &tty_attr) < 0) {
- perror("tcgetattr:");
- exit(EX_OSERR);
- }
-
- /* end of if(tcsetattr(&tty_attr)) */
- /* get window size */
- if (ioctl(fileno(stdout), TIOCGWINSZ, &window_size) < 0) {
- perror("ioctl stdout:");
- exit(1);
- }
-
- child_pid = forkpty(&pty_master, NULL, &tty_attr, &window_size);
- } /* end of if(isatty(fileno(stdin))) */
- else { /* not interactive */
- child_pid = forkpty(&pty_master, NULL, NULL, NULL);
- }
-
- if (child_pid < 0) {
- perror("forkpty():");
- fflush(stdout);
- fflush(stderr);
- exit(EX_OSERR);
- } /* end of if(child_pid < 0) */
- if (child_pid == 0) {
- /* in the child */
- struct termios s_tty_attr;
- if (tcgetattr(fileno(stdin), &s_tty_attr)) {
- perror("Child:");
- fflush(stdout);
- fflush(stderr);
- exit(EXIT_FAILURE);
- }
- /* Turn off echo */
- s_tty_attr.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
- /* Also turn of NL to CR?LF on output */
- s_tty_attr.c_oflag &= ~(ONLCR);
- if (tcsetattr(fileno(stdin), TCSANOW, &s_tty_attr)) {
- perror("Child:");
- exit(EXIT_FAILURE);
- }
- { /* There is no reason to block sigchild for the process we
- shall exec here */
- sigset_t chld_signal_set;
- /* release SIGCHLD */
- sigemptyset(&chld_signal_set); /* no signals */
- sigaddset(&chld_signal_set, SIGCHLD); /* Add sig child */
- sigprocmask(SIG_UNBLOCK, &chld_signal_set, NULL); /* Unblock the signal */
- }
-
- if (execvp(argv[1], argv + 1)) {
- perror("Exec:");
- fflush(stdout);
- fflush(stderr);
- exit(EXIT_FAILURE);
- }
- }
-
- /* end of if(child_pid == 0) */
- /*
- * OK. Prepare to handle IO from the child. We need to transfer
- * everything from the child's stdout to ours.
- */
- FD_ZERO(&readfds);
- FD_ZERO(&writefds);
- FD_ZERO(&exceptfds);
-
- /*
- * Read current file descriptor flags, preparing to do non blocking reads
- */
- retval = fcntl(pty_master, F_GETFL);
- if (retval < 0) {
- perror("fcntl_get");
- fflush(stdout);
- fflush(stderr);
- exit(EX_IOERR);
- }
-
- /* Set the connection to be non-blocking */
- if (fcntl(pty_master, F_SETFL, retval | O_NONBLOCK) < 0) {
- perror("fcnt_setFlag_nonblock:");
- fflush(stdout);
- fflush(stderr);
- exit(1);
- }
-
- FD_SET(pty_master, &readfds);
- FD_SET(pty_master, &writefds);
- FD_SET(fileno(stdin), &readfds);
- if (isatty(fileno(stdin))) {
- if (tty_semi_raw(fileno(stdin)) < 0) {
- perror("Error: settingraw mode:");
- fflush(stdout);
- fflush(stderr);
- } /* end of if(tty_raw(fileno(stdin)) < 0) */
- if (atexit(tty_atexit) < 0) {
- perror("Atexit setup:");
- fflush(stdout);
- fflush(stderr);
- } /* end of if(atexit(tty_atexit) < 0) */
- }
-
- /* ignore return from nice, but lower our priority */
- int ignore __attribute__ ((unused)) = nice(19);
-
- /* while no signal, we loop around */
- int done = 0;
- while (!done) {
- struct timeval interval;
- fd_set t_readfds;
- fd_set t_writefds;
- fd_set t_exceptfds;
- /*
- * We still use a blocked signal, and check for SIGCHLD every
- * loop, since waiting infinitely did not really help the load
- * when running, say, top.
- */
- interval.tv_sec = 0;
- interval.tv_usec = 200000; /* so, check for signals every 200 milli
- seconds */
-
- t_readfds = readfds;
- t_writefds = writefds;
- t_exceptfds = exceptfds;
-
- /* check for the signal */
- retval = sigtimedwait(&signal_set, &signalinfo, &timeout);
-
- if (retval == SIGCHLD) {
- /* child terminated */
- done = 1; /* in case they do not close off their
- file descriptors */
- } else {
- if (retval < 0) {
- if (errno != EAGAIN) {
- perror("sigtimedwait");
- fflush(stdout);
- fflush(stderr);
- exit(EX_IOERR);
- } else {
- /* No signal in set was delivered within the timeout period specified */
- }
- }
- } /* end of else */
-
- if (select
- (pty_master + 1, &t_readfds, &t_writefds, &t_exceptfds,
- &interval) < 0) {
- perror("Select:");
- fflush(stdout);
- fflush(stderr);
- exit(EX_IOERR);
- }
-
- if (FD_ISSET(pty_master, &t_readfds)) {
- retval = read(pty_master, buf, (unsigned int)16384);
- if (retval < 0) {
- if (errno != EINTR && errno != EAGAIN) { /* Nothing left to read? */
- fflush(stdout);
- fflush(stderr);
- /* fprintf(stderr, "DEBUG: %d: Nothing left to read?\n", __LINE__); */
- exit(EXIT_SUCCESS);
- } /* end of else */
- } /* end of if(retval < 0) */
- else {
- if (retval == 0) {
- if (++err_count > 5) { /* child closed connection */
- fflush(stdout);
- fflush(stderr);
- /*fprintf(stderr, "DEBUG: %d: child closed connection?\n", __LINE__); */
- exit(EXIT_SUCCESS);
- }
- } /* end of if(retval == 0) */
- else {
- ssize_t nleft = retval;
- ssize_t nwritten = 0;
- char *ptr = buf;
- while (nleft > 0) {
- if ((nwritten =
- write(fileno(stdout), ptr,
- (unsigned int)nleft))
- <= 0) {
- if (errno == EINTR) {
- nwritten = 0;
- } /* end of if(errno == EINTR) */
- else {
- perror("write");
- fflush(stdout);
- fflush(stderr);
- exit(EXIT_SUCCESS);
- } /* end of else */
- } /* end of if((nwritten = write(sockfd, ptr, nleft)) <= 0) */
- nleft -= nwritten;
- ptr += nwritten;
- } /* end of while(nleft > 0) */
-
- /* fprintf(stderr, "DEBUG: %d: wrote %d\n", __LINE__, retval); */
- fflush(stdout);
- } /* end of else */
- } /* end of else */
- }
- if (FD_ISSET(fileno(stdin), &t_readfds)) {
- if (FD_ISSET(pty_master, &t_writefds)) {
- retval =
- read(fileno(stdin), buf,
- (unsigned int)16384);
- if (retval < 0) {
- if (errno != EINTR && errno != EAGAIN) { /* Nothing left to read? */
- fflush(stdout);
- fflush(stderr);
- exit(EXIT_SUCCESS);
- } /* end of else */
- } /* end of if(retval < 0) */
- else {
- if (retval == 0) {
- if (++err_count > 5) { /* lost controlling tty */
- fflush(stdout);
- fflush(stderr);
- exit(EXIT_SUCCESS);
- }
- } /* end of if(retval == 0) */
- else {
- ssize_t nleft = retval;
- ssize_t nwritten = 0;
- char *ptr = buf;
- while (nleft > 0) {
- if ((nwritten =
- write(pty_master,
- ptr,
- (unsigned
- int)nleft))
- <= 0) {
- if (errno ==
- EINTR) {
- nwritten
- = 0;
- } /* end of if(errno == EINTR) */
- else {
- perror
- ("write");
- fflush
- (stdout);
- fflush
- (stderr);
- exit(EXIT_SUCCESS);
- } /* end of else */
- } /* end of if((nwritten = write(sockfd, ptr, nleft)) <= 0) */
- nleft -= nwritten;
- ptr += nwritten;
- } /* end of while(nleft > 0) */
-
- fflush(stdout);
- } /* end of else */
- } /* end of else */
- } /* end of if(FD_ISSET(pty_master, &writefds)) */
- } /* something to read on stdin */
- } /* Loop */
-
- fflush(stdout);
- fflush(stderr);
-
- exit(EXIT_SUCCESS);
-} /* end of main() */
--
1.7.10
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.
^ permalink raw reply related [flat|nested] 4+ messages in thread